SEOUL — A novel PET radiotracer, 18F-GP1 PET/CT, accurately detected deep vein thrombosis in the legs and identified whether clots had migrated to the lungs in a study of 46 symptomatic patients. The findings were presented at the Society of Nuclear Medicine and Molecular Imaging (SNMMI) 2026 Annual Meeting.
The study assessed the diagnostic accuracy and tolerability of 18F-GP1 PET/CT for identifying acute lower extremity deep vein thrombosis. Researchers compared diagnostic performance for thigh clots with venous ultrasound and also evaluated accuracy for calf clots and the detection rate of pulmonary embolism. Three blinded nuclear medicine physicians independently reviewed the scans.
18F-GP1 PET/CT showed high diagnostic accuracy for detecting clots in both the thigh and calf. It also demonstrated a high detection rate of pulmonary embolism occurring alongside deep vein thrombosis. The radiotracer was well tolerated, with no drug-related adverse events reported. "These findings suggest that a single whole-body PET scan could accurately evaluate clots in both the legs and lungs at the same time, potentially reducing the need for multiple tests while improving patient convenience," said Sangwon Han, clinical assistant professor, Department of Nuclear Medicine, Asan Medical Center, University of Ulsan College of Medicine.
Unlike conventional imaging techniques such as venous ultrasound and CT—which rely on indirect structural changes—18F-GP1 PET/CT directly visualizes blood clots by selectively targeting activated platelets. This thrombus-specific imaging agent enables whole-body imaging of clots in a single scan, including in areas difficult to assess with standard methods. Giuseppe Esposito, SNMMI Scientific Program Committee chair, said the technology could extend beyond deep vein thrombosis. "This approach could serve as a platform technology for detecting clots throughout the body and even help to detect stroke or cardiovascular disease." He added, "These images show just how powerful molecular imaging can be."
The collection of images demonstrating clot visualization in the legs and lungs using 18F-GP1 PET/CT was selected as the 2026 SNMMI Henry N. Wagner, Jr., Image of the Year. The radiotracer has already been evaluated in Phase 2 studies for deep vein thrombosis, embolic stroke, and cardiovascular disease. With further validation through larger, multicenter Phase 3 trials, 18F-GP1 PET/CT could become part of routine clinical practice within the next five to 10 years.